Bacteria and Fungi associated with the deterioration of Cocoyam Colocasia esculenta (Taro)

Abstract

Aim: To isolate and identify the bacteria and fungi associated with the deterioration of Cocoyam with their respective percentage occurrences. Method: Cocoyam Colocasia esculenta (Taro) corms were obtained from a local barn in Umuahia, Abia State Nigeria and transported aseptically to the laboratory for further microbiological analysis. Sterile knife and forceps were used to obtain spoilt tissues from the cocoyam corms. A portion of the spoilt part of the cocoyam was cut out using the sterile knife and was inoculated into Nutrient agar and MacConkey agar plate for growth of bacteria. Another piece of the cocoyam was placed on potato dextrose agar for growth of fungi. Results: Bacterial isolates such as to Escherichia coli, Klebsiella pneumonia, Staphylococcus epidermidis, Staphylococcus aureus, Serratia marcescen and Bacillus subtilis were isolated from the samples. While fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer and Rhodotorula spp were equally isolated. Staphylococcus aureus had highest number of microbial isolate with total number of 8 (19.0%), follow by Klebsiella pneumonia with microbial isolate of 7 (16.7%), Escherichia coli and Aspergillus niger had 6 microbial isolate with frequency of (14.3%) each respectively, while Serratia marcescens, Rhodotorula spp while Aspergillus flavus had the least microbial isolate of 1 (2.4%). The presence of these organisms are responsible for the deterioration of cocoyam. Conclusion: Microbiological changes takes place during the storage of Cocoyam Colocasia esculenta (Taro). Therefore, there is need for better processing, handling techniques, good hygiene practices, safety and storage of the finished product. Findings obtained may be useful in the handling and storage of Cocoyam flour.